Benchmark: JavaScript spread operator vs Object.assign performance no write over more props

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world', a:'a', b:'b', c:'c',d:'d'} const secondObject = { moreData: 'foo bar',e:'e', f:'f', g: 'g' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world', a:'a', b:'b', c:'c',d:'d'} const secondObject = { moreData: 'foo bar',e:'e', f:'f', g: 'g' } const finalObject = Object.assign(Object.assign({}, firstObject), secondObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**What is being tested?**

The benchmark compares the performance of two approaches to merge two objects: using the spread operator (`...`) and using `Object.assign()`. The test cases are identical, with two objects being merged into a single object.

**Options compared:**

1. **Using the spread operator**: This method uses the spread operator (`...`) to create a new object with the properties of both objects.
2. **Using Object.assign()**: This method uses the `Object.assign()` function to merge the properties of two objects into a new object.

**Pros and cons of each approach:**

1. **Using the spread operator:**
	* Pros:
		+ Concise and readable syntax
		+ Creates a new object, which can be beneficial for performance (no mutation)
	* Cons:
		+ Can be slower than `Object.assign()` due to the creation of a new object
2. **Using Object.assign():**
	* Pros:
		+ Fast and efficient, as it only merges references to existing properties
	* Cons:
		+ Mutates the original objects (both source objects are modified)
		+ Requires careful handling of null or undefined values

**Other considerations:**

1. **Library usage:** There is no explicit library mentioned in the benchmark definition or test cases.
2. **Special JS features/syntax:** The use of the spread operator (`...`) is a modern JavaScript feature, introduced in ECMAScript 2018 (ES2018). This means that browsers with older versions may not support it.

**Other alternatives:**

1. **Object.create()**: Another way to merge objects using `Object.create()` and `Object.assign()`.
2. **lodash.merge()**: A popular utility library from Lodash that provides a concise way to merge objects, including the spread operator method.
3. **ES6 Object Rest Spread Operator (Rest Parameter)**: Similar to the spread operator, but used with function parameters instead of object literals.

These alternatives may offer different trade-offs in terms of performance, readability, and maintainability, depending on the specific use case.

Related benchmarks:

JavaScript spread operator vs Object.assign performance no write over more props (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 5 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):